1. Field of the Invention
The present invention relates to an image forming apparatus capable of computing power consumption thereof, and a control method and a storage medium therefor.
2. Description of the Related Art
In recent years, image forming apparatuses such as printers have been demanded to reduce power consumption thereof for reduction of emission of greenhouse gas such as carbon dioxide. To this end, it is necessary to grasp power consumptions of individual image forming apparatuses at the time of image formation. However, if an externally-attached power meter or a built-in power meter is provided in each of individual image forming apparatuses, a problem of increased cost is caused.
Japanese Laid-open Patent Publication No. 2010-4382 discloses a power measurement system including an image forming apparatus with no power meter and an image forming apparatus with power meter, which are network-connected with each other. This system estimates power consumption of the image forming apparatus with no power meter which is consumed when the apparatus is in a sleep state on the basis of power consumption of the image forming apparatus with power meter measured by the power meter and consumed when the apparatus is in a sleep state.
With the power measurement system, power consumption of the image forming apparatus consumed when the apparatus is in a sleep state can be estimated, but power consumption thereof consumed when the apparatus executes a print job cannot accurately be computed.
Japanese Laid-open Patent Publication No. 2010-72253 discloses a power consumption calculation method in which a work load of a job executed by an image forming apparatus is measured and a power consumption amount corresponding to one job execution is calculated based on the measured work load and state transition data that indicates power consumption and a required time for each of states of the image forming apparatus.
Power consumption differs depending on print job contents. For example, power consumption differs between monochrome text printing on an A4 sheet and color graphic printing on a postcard due to a difference in fixing device temperature and a difference in sheet conveyance motor speed. Nevertheless, the above-described power consumption calculation method cannot compute power consumption that reflects factors affecting the power consumption.
As described above, conventional techniques have a problem that power consumption of image forming apparatus cannot be computed with accuracy.